Renal Pathology Chapter 21 Part 1 Flashcards Preview

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Flashcards in Renal Pathology Chapter 21 Part 1 Deck (76)
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Renal pelves, ureters, bladder, and urethra (except terminal portion) lined by

-special form of transitional epithelium called urothelium


Urothelium is composed of

-5-6 layers of cells with oval nuclei, often with linear nuclear grooves, and a surface layer consisting of large, flattened "umbrella cells" with abundant cytoplasm
-epithelium rests on a well-developed basement membrane, beneath which is a lamina propria


Lamina propria in the urinary bladder contains

-wisps of smooth muscle that form discontinuous muscularis mucosae


If urine flow is obstructed and intravesical pressures rise,

-the bladder musculature undergoes hypertrophy


Retroperitoneal tumors or fibrosis may

may entrap the ureters, sometimes obstruct them


As ureters enter the pelvis,

they pass anterior to either the common iliac or the external iliac artery


In the female pelvis, the ureters

lie close to the uterine arteries and are therefore vulnerable to injury in operations on the female genital tract


3 points of slight narrowing of ureters

-at the ureteropelvic junction, where they enter the bladder, and where they cross the iliac vessels
-renal calculi may become impacted in these spots when they pass form the kidney to the bladder


As the ureters enter the bladder,

they pursue an oblique course, terminating in a slit-like orifice
-obliquity of this intramural segment of the ureteral orifice permits the enclosing bladder musculature to act like a sphincteric valve, blocking the upward reflux of urine even in the presence of marked distention of the urinary bladder


A defect in the intravesical portion of the ureter leads to

vesicoureteral reflux


In middle-aged and older women, relaxation of pelvic support leads to

prolapse (descent) of the uterus, pulling with it the floor of the bladder
-in this fashion, the bladder is protruded into the vagina, creating a pouch (cystocele) that fails to empty readily with micturition


Double ureters

-almost invariably associated with totally distinct double renal pelves or with the anomalous development of a large kidney having a partially bifid pelvis terminating in separate ureters
-may pursue separate course to the bladder, but commonly are joined within the bladder wall and drain through a single ureteral orifice
-most are unilateral and of no clinical significance


Ureteropelvic junction (UPJ) obstruction

-congenital disorder that is the most common cause of hydronephrosis in infants and children
-cases that present early in life are bilateral in 20% of cases, are often associated with other congenital anomalies, and preferentially occur in males
-agenesis of the contralateral kidney in a minority of cases
-in adults, more common in women and often unilateral


UPJ obstruction has been ascribed to

abnormal organization of smooth muscle bundles at the UPJ, to excess stromal deposition of collagen between smooth muscle bundles, or rarely to congenitally extrinsic compression of the UPJ by the renal vessels.



-saccular outpouchings of the ureteral wall
-may be congenital or acquired
-most are asymptomatic, but urinary stasis within diverticula sometimes leads to recurrent infection



-associated with inflammation
-typically not associated with infection and is of little clinical consequence


Ureteritis Follicularis

-accumulation or aggregation of lymphocytes forming germinal centers in the sub epithelial region may cause slight elevations of the mucosa and produce a fine granular mucosal surface


Ureteritis cystica

-at other times the mucosa may become sprinkled with fine cysts varying in a diameter from 1-5 mm lined by flattened urothelium


Small benign tumors of the ureter are generally of

mesenchymal origin


Fibroepithelial polyp

-tumor-like lesion that presents as a small mass projecting into the lumen, often in children
-occurs more commonly in the ureters but may also involve the bladder, renal pelves, and urethra
-polyp is composed of loose, vascularized connective tissue overlaid by urothelium


Primary malignant tumors of the ureters resemble

those arising in the renal pelvis, calyces, and bladder
-majority are urothelial carcinomas.
-occur most frequently during the 6th or 7th decades of life and cause obstruction of the ureteral lumen
-sometimes multifocal and commonly occur concurrently with similar neoplasms in the bladder or renal pelvis


Unilateral obstruction of the ureter

-typically results from proximal causes


Bilateral Obstruction of the ureter

arises from distal cause, such as nodular hyperplasia of the prostate


Sclerosing Retroperitoneal Fibrosis

-uncommon cause of ureteral narrowing or obstruction and is characterized by a fibrotic proliferative inflammatory process encasing the retroperitoneal structures and causing hydronephrosis
-occurs in middle to late age and is more common in males
-at least a subset related to IgG4-related disease
-Often involves other tissues, particularly exocrine organs such as the pancreas and salivary glands
-can also be associated with drug exposures, adjacent inflammatory conditions, or malignant disease


Vesicoureteral reflux

most common and serious urinary bladder congenital anomaly
-major contributor to renal infection and scarring and in consideration of pyelonephritis


Congenital diverticula of the bladder

-may be due to a focal failure of development of the normal musculature or to some urinary tract obstruction during fetal development


Acquired diverticula

-most often seen with prostatic enlargement producing obstruction to urine outflow and marked muscle thickening of the bladder wall
-increased intravesical pressure causes outputting of bladder wall


Exstrophy of the bladder

-developmental failure in the anterior wall of the abdomen and the bladder, so that the bladder either communicates directly through a large defect with the surface of the body or lies as an opened sac
-exposed bladder mucosa may undergo colonic glandular metaplasia and is subject to infections that often spread to upper levels of the urinary system
-patients have an increased risk of adenocarcinoma arising in the bladder remnant


Urachal anomalies

-urachus remains patent
-when totally patent, a fistulous urinary tract connects the bladder with the umbilicus
-in other instances, only the central region of the arches persist, giving rise to urachal cysts, lined by either urothelium or metaplastic glandular epithelium


Bacterial pyelonephritis is frequently preceded by

-infection of the urinary bladder, with retrograde spread of microorganisms into the kidneys and their collecting systems
-common agents are E. coli, Proteus, Klebsiella, and Enterobacter
-Women more likely to develop cystitis as a result of shorter urethras